Update cython requirement from <4,>=3.1 to >=3.1.8,<4

Updates the requirements on [cython](https://github.com/cython/cython) to permit the latest version.
- [Release notes](https://github.com/cython/cython/releases)
- [Changelog](https://github.com/cython/cython/blob/master/CHANGES.rst)
- [Commits](cython/cython@3.1.0...3.1.8)

---
updated-dependencies:
- dependency-name: cython
  dependency-version: 3.1.8
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

pyproject.toml

@@ -3,7 +3,7 @@
 
 [build-system]
 requires = [
-    "Cython < 4, >= 3.1",
+    "Cython >= 3.1.8, < 4",
     "setuptools >= 61",
 ]
 build-backend = "setuptools.build_meta"

requirements-dev.txt

@@ -1,6 +1,6 @@
 build
 colorama == 0.4.*
-cython < 4, >= 3.1
+cython >= 3.1.8, < 4
 more_itertools == 11.*
 mypy
 setuptools >= 61